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Comment by rr888 | Hacker News Reader

I'm thinking Solar is going to be our main renewable energy resource. It sucks for heating in winter and transportation. Hydrogen definitely is a great solution for these problems, just need to improve the efficiency of turning electricity into H.

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IMHO, the easiest way forward that makes sense from an engineering as well as financial standpoint: overbuild as much energy capture as possible: solar, wind, nuclear, doesn't matter as long as it is captured at a location where it is cheap and convenient to do so. Then use power-to-gas tech and get a well behaved hydrocarbon fuel which is easy to transport anywhere in the world, stores energy at a high density in a relatively safe way, and can be used in practically all applications. And yes the conversion is super inefficient, which is why you need the energy capture to be cheap and to have maybe 300% of needed capacity.

Methane or Ammonia.

Cow farts affecting climate: solved.

It is climate neutral if you make it from renewable electricity and you burn it afterwards.

It's cow burps that were an issue, but manure is already used to create carbon negative fuels and/or hydrogen while cutting pollution:

https://www.historylink.org/File/20270

Thanks, this is what I was trying to say but you did it better. :) Its fascinating things like Steel Mills which require a lot of heat are probably best located in deserts.

is this: https://en.wikipedia.org/wiki/Hydrogen_embrittlement solved?

seems like it would be easily solvable with a plastic coating, right?

Hydrogen fuel tanks already have an inner liner to prevent this.

Hydrogen will go through plastics, in fact plastic containers need a metal coating to contain hydrogen effectively.

https://en.wikipedia.org/wiki/Hydrogen_embrittlement#Prevent... is a good start.

It seems to be mostly a solved issue if you use the right materials and design: https://en.m.wikipedia.org/wiki/Hydrogen_pipeline_transport#...

Electricity can run heat pumps which are great for heating. Even better if its a water-to-ground loop underneath the building, if there is no existing district heating system.

Wind is the most efficient renewable, followed by geothermal, hydro, and then solar. Solar is nice in extremely sunny places but otherwise it's more of a back-up.

Sure :)

https://solaredition.com/wp-content/uploads/2020/12/2.png

96% of H2 produced from carbon sources.

How far do you think we can stretch electrolysis efficiency ? So far we are at 50% https://www.linkedin.com/pulse/actual-efficiency-electrolysi...

And you need to compress H2 even more to make it interesting to transport, making it even less efficient.

But lets follow our technical dreams where we will have 90% of H2 produced by solar panels (that doesn't have any impact on their own).

We just need to travel to a solar system with a gas giant from which we can siphon Hydrogen directly, 'duh.

Should be easy, right?

Jupiter, Saturn, Uranus and Neptune have a lot of it already.

Don't need to go that far, we could put giant solar panels that would soak up sunlight 24/7 and transmit that to earth. I see it work on small scale experiments, I really think that is SpaceX's ultimate game plan. Only those with capacity to deliver payloads at scale will be capable of building these energy stations.

How they would deal with objects, meteorites and repairing is another concern but I'd imagine it won't be a giant solar panel but modular ones that are floating in cluster

Cost matters a lot more than efficiency. The two are related, but not the same. The correct question to ask is how much does a kWh of hydrogen cost, and how much lower can we get that.

> 96% of H2 produced from carbon sources

Yes this is crazy, there is no point using Hydrogen right now.

Solar panels are getting so cheap so quickly that in sunny places electricity during the day will be virtually free. 50% efficiency is pretty good in that case.

50% of current H2 is used for refining fossil fuels.

And, much like solar, it's not some random efficiency or capacity stat that matters, it's cost. Low cost electrolizers are the next big thing that will prompt Americans to ask "Why is China the world leader in this technology we've been ignoring or actively spreading lies about?"

https://www.spglobal.com/commodityinsights/en/market-insight...

Efficiency is not so important, solar is cheap.

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